A time-to-voltage converter and analog memory for colliding beam detectors

A novel CMOS integrated circuit which measures the time interval between two digital voltage pulses and stores the result as an analog voltage is described. Resolution of the circuit is in the subnanosecond range. An additional feature of the circuit is a storage depth of eight samples, i.e. eight consecutive time measurements can be recorded individually and saved in an analog memory. A CMOS time-integration circuit based on saturation-region current switching performs very well, demonstrating that CMOS is well suited for this type of application. The time-to-voltage converter architecture is also easily expandable to implement the analog memory.>